Not 100% positive on this one so i'm sure someone will correct if im wrong, but The AEM
improves power at the top end of the RPM band where as the Injen
improves low end power. The Intake
is definately worth it, with a k&n filter you can just clean and re-use. Power is definately noticable, if you do the cold air, i'd recommend the air bypass valve just incase the filter takes on some heavy rain, or water.